Boiler.



No. 539,390. Patented Dec. I9, I899.

B. HULT.

BOILER.

(Application filed June 8, 1898.) f N 0 M 0 d 9] wwwwoe/a, a

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BENJAMIN HOLT, OF'STOOKTON, CALIFORNIA.

BOILER.

SPECIFICATION forming part of Letters Patent No. 639,390, dated December19, 1899. Application filed June 8, 1899. Serial No. 719,790. No model.)

To all whom it may concern.-

Be it known that LBENJAMIN HOLT, a citizen of the United States,residing at Stockton, county of San Joaquin, State of California, haveinvented an Improvement in Boilers; and I hereby declare the followingto be a full, clear, and exact description of the same.

My invention relates to improvements in boilers, these improvements, asherein shown, being especially designed for what are known as portableboilers but they are also applicable to all boilers of that class havingwater-legs extending down upon each side of the furnace andcombustion-chamber below the boiler.

The invention consists,essentially,in an improved means for connectingthe sheet forming the water-leg sections with the cylindrical shell ofthe boiler.

It also comprises details of construction, which will be more fullyexplained by reference to the accompanying drawings, within which-Figure 1 is a side elevation. Fig. 2 is a vertical half-section showingthe connection of the water-leg sheets with the boiler-shell. Fig. 3 isa vertical half-section and elevation taken at the rear end of theboiler. Figs. 4 and 5 show a perspective view and section, respectively,of the block H.

A is the shell of the boiler, and B B are walls riveted to the sidesof-the boiler, forming supplemental water spaces extending down uponeach side and of a length equal to or greater than that of the boiler.The lower edges and ends of these sheets are closed, as shown at O, andthey thus form open channels extending upon each side of the boiler andupward along the sides thereof, with openings at intervals connectingthe interior of the boilerwith the space between these plates, theextensions being known as water-legs. The outer sheet extends upwardlyand is riveted to the shell of the boiler at a point somewhat above thecentral horizontal line and is connected therewith, as also is the innersheet B where it extends below the boiler, by staybolts in any suitableor desired manner.

The boiler is here shown as having fines extending through from one endto the other, and the space between the water-legs at the front end ofthe boiler receives the grate and forms the furnace for the combustionof fuel. At a point behind the center of the boiler these Water-legs areconnected by an oval tubular passage D, so that water may circulatefreely from one leg to the other through this passage, and thispassageis centrally connected by pipes E with the lower part of the rearportion of the boiler.

The rear extension behind the boiler forms a combustion-chamber, intowhich the products of combustion pass beneath the boiler from the grateand are thence returned through 'the tines to the smoke-box F at thefront, thence passing out through the stack or chimney G.

The general construction of the boiler is not very different from otherboilers of this class. My main improvement consists in a means forsecuring the water-legplates B to the boiler-shell, so as to provide fora larger space at the junction of the water-leg with the boiler-shell,to increase the strength of the fastening, and to so place the lines ofriveting by which the plates are united to the boiler-shell that theycan be easily reached from the outside instead of being riveted withinthe narrow space between the plates, and the invention also comprises ameans for obtaining access to the interior of these water-legs, so as toclean them of scale and other deposits.

As shown in section, Fig. 2, the plates B are curved at the top, asshown at b, and their edges meet the lower portion of the curve of thecylindrical shell of the boilerin a line essentially coincidenttherewith. The line of rivets then passes through holes made in theshell of the boiler and through the edges of these plates, the outerhead of the rivet being thus made accessible from the space between thewater-legs, and in this manner the riveting is better done than Where itis necessary to work in the narrow space between the outer sheet of thewater-leg and the lower side of the boiler. This curvature also providesfor the increased space at the junction of these plates, and a body ofwater will thus rest upon this curve and will pro tect the iron frombeing burned by the fierce heat within the furnace. The front and rearend of the water-legs are closed, as shown at O, and at the rear end thetriangular space formed between the curves 1), the outer plate I5, andthe cylindrical shell of the boiler must be closed by a separate block.The block is shown in perspective at II and fits between the meetingportions of the boiler-shell, the plate B, and the curve I) and isriveted thereto, as shown. This block is made of considerable thickness,and in order to prevent its being burned by the exterior heat I haveshown holes h bored into it from the interior and extending part waythrough, so that water from within the waterlegs can enter thesechambers, and thuskeep the block sufficiently cool for the purpose.

In order to obtain access to the space within the water-legs, I haveshown holes I made through the ends of the water-legs and closed byscrew plugs J, which screw into these holes and close them. These plugsare removable at any time for the insertion of rods orscrapers, whichmay be directed through the spaces between the stay-bolts, thuscleansing 01? scale and deposit from the sides of the water-legs andkeeping them measurably clean. These water-legs serve as a sort ofheater and purifier for the water, as the ma- .jority of the scale ordeposit from the water will remain within 'these legs and will not enterthe boiler.

I Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a boiler, a complete cylindrical shell, independent water-legs ateach side having a length equal to or greater than that of theboiler,the inner walls of said legs being curved throughout the lengthof the boiler, to meet the lower part of the boiler-shell, and rivetedthereto.

2. In a boiler, a complete cylindrical shell,

independent water-legs at each side having a length equal to or greaterthan that of the boiler, the inner walls of said legs forming concavearches into the space between the Water-legs, and having their edgesriveted to the boiler-shell.

3. The combination with a cylindrical boiler having a continuous shell,of independent vertical water-legs extending along the sides of theboiler with the outer and inner walls riveted thereto, the inner wallshaving their upper edges curved to form concave arches into the spacebeneath the boiler, and form stays therefrom.

4. In a boiler, a cylindrical shell, waterlegs composed of outer andinner plates se- 'cu red to the sides of the boiler, in lines above andbelow the central horizontal plane there through, said inner plateshaving their upper edges curved inwardly and riveted to the boiler-shellwithin the space between the water-legs, and triangular blocks fittingthe open the interior for the admission of. water thereinto. I

In witness whereof I have hereunto set my hand.

BENJAMIN HOLT. Witnesses:

JOSEPHINE M. HOGAN, G. L. DICKENSON.

